When pondering just how audio trends have evolved over the years you’ll quickly discover that the one area experiencing the most dramatic evolution is that of the subwoofer. At first we didn’t even bother with them, then thanks to the pioneers of the industry we began taking them from our homes and studios and mounting them in our cars. Around that time we thought bigger was better so they became larger, more power hungry and just when our subwoofers were rivaling our tyres in diameter, the trends changed again to smaller units which could be stealthy hidden away behind seats where the depths were tight but still acceptable enough to allow for a subwoofer.


Some of the more creative companies started experimenting with ultra-thin subwoofers that could fit under seats. The evolution continued but soon ran head-long into another facet that was quickly evolving too; factory stereos. They’ve also come a long way over the years and we’re now at a point where they’re utilising amplifiers and split systems in order to sound very impressive with some very big names putting their stamp on this development.

However whether due to budgetary or space restraints; the sub-bass tends to lose out with many factory enclosures sounding terrible to say the least. This in turn led to the craftier manufactures turning their attention to developing subwoofer systems that could simply interface with the factory stereos. Focal are one of the leaders of this pack, especially in active subwoofer systems (active means the amplifier running the subwoofer is built into the enclosure itself). Starting out initially with the BUS20 8-inch and BUS25 10-inch designs a couple of years ago, Focal introduced this line to a very appreciative audience.

It had developed a line of true under seat subwoofers which actually sounded natural and clean – a feat that had yet to be achieved by any true under-seat subwoofer (i.e. just calling an 8-inch high enclosure ‘under-seat’ doesn’t make it so). Additionally, although these systems could interface with many factory stereos, you still needed an experienced installer to fit them as there was much cutting, soldering and heat shrinking required to make them work. This is where Focal’s latest creation has pushed into a territory all of its own. With the emergence of the new iBus20 from Focal not only has there been a massive improvement in the subwoofer and enclosure design itself, there has also been a large step-up in the plug and play side of things.

The iBus20 is quite simply a huge step-up from the BUS20 and BUS25 designs and instead of going with the bigger is better approach Focal instead concentrated on the 8-inch woofer (200m or ‘20’ part number). It has the mindset that a slightly smaller subwoofer with a longer excursion will allow for much lower sub-bass extension than a large subwoofer which would output more volume but not go as low. Remember these units are not about high output bass rather just filling out the bottom octave in your factory system.

To this end the iBus20 has a new connection system which allows it to connect to many cars boasting Euro plugs such as Volkswagen, Alfa, Peugeot, Renault and so on. You simply plug your car’s existing loom into the iBus loom plug and then plug the iBus loom back into the car. Of course there are always exceptions to the rule so it’s always best to consult with a professional installer before you go unplugging things all over your new car.

Unpacking the more colourful and decorated cardboard box than offered previously, you’re met with a much more industrial-looking unit. The smooth rounded edges of the BUS20 are long gone with the iBus20 looking more like a large amplifier than a subwoofer enclosure. The case is made from aluminium and is rectangular in shape measuring 71.5mm x 344mm x 250mm. On the top of the enclosure at one end there’s an 8-inch grille with the Focal logo embossed on top, while along the sides there are two small lines just to decorate the shape a little.

Along the sides are the heatsinks which dissipate heat from the internally-mounted 75 watt (150 watt maximum) amplifier. Before you scoff at the power rating remember Focal has employed a new driver with very efficient suspension meaning it doesn’t require 1000 watts to make it move. Along the front end are all the inputs and outputs including power, earth, remote and RCA (when using an aftermarket head unit) or a high-level input plug (if using a factory head unit speaker outputs). There are additional controls built into the unit such as a 50Hz – 150Hz low pass filter and input port for a remote bass level controller. Lastly; there’s 0 – 180 degree phase control which comes in most handy for adjusting the subwoofer output to project forward in line with the rest of your front stage. This is for factory head units rather than aftermarket ones as the latter tend to employ time alignment as part of their DSP package.